====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/16936 is trying to acquire lock: 00000000340eb6d0 (&p->lock){+.+.}, at: seq_read+0x6b/0x11c0 fs/seq_file.c:164 but task is already holding lock: 00000000040ef17f (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2779 [inline] 00000000040ef17f (sb_writers#3){.+.+}, at: do_sendfile+0x97d/0xc30 fs/read_write.c:1446 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (sb_writers#3){.+.+}: sb_start_write include/linux/fs.h:1579 [inline] mnt_want_write+0x3a/0xb0 fs/namespace.c:360 ovl_do_remove+0xf0/0xdb0 fs/overlayfs/dir.c:845 vfs_rmdir.part.0+0x10f/0x3d0 fs/namei.c:3882 vfs_rmdir fs/namei.c:3868 [inline] do_rmdir+0x3fd/0x490 fs/namei.c:3943 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&ovl_i_mutex_dir_key[depth]#2){++++}: inode_lock_shared include/linux/fs.h:758 [inline] do_last fs/namei.c:3326 [inline] path_openat+0x17ec/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_open_execat+0x11d/0x5b0 fs/exec.c:853 __do_execve_file+0x1a8b/0x2360 fs/exec.c:1770 do_execveat_common fs/exec.c:1879 [inline] do_execve+0x35/0x50 fs/exec.c:1896 __do_sys_execve fs/exec.c:1977 [inline] __se_sys_execve fs/exec.c:1972 [inline] __x64_sys_execve+0x7c/0xa0 fs/exec.c:1972 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&sig->cred_guard_mutex){+.+.}: lock_trace fs/proc/base.c:402 [inline] proc_pid_syscall+0xb8/0x2f0 fs/proc/base.c:635 proc_single_show+0xeb/0x170 fs/proc/base.c:755 seq_read+0x4e0/0x11c0 fs/seq_file.c:232 do_loop_readv_writev fs/read_write.c:701 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_read+0x471/0x630 fs/read_write.c:925 vfs_readv+0xe5/0x150 fs/read_write.c:987 do_preadv fs/read_write.c:1071 [inline] __do_sys_preadv fs/read_write.c:1121 [inline] __se_sys_preadv fs/read_write.c:1116 [inline] __x64_sys_preadv+0x22b/0x310 fs/read_write.c:1116 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&p->lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:937 [inline] __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078 seq_read+0x6b/0x11c0 fs/seq_file.c:164 proc_reg_read+0x1bd/0x2d0 fs/proc/inode.c:231 do_loop_readv_writev fs/read_write.c:701 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_read+0x471/0x630 fs/read_write.c:925 vfs_readv+0xe5/0x150 fs/read_write.c:987 kernel_readv fs/splice.c:362 [inline] default_file_splice_read+0x457/0xa00 fs/splice.c:417 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &p->lock --> &ovl_i_mutex_dir_key[depth]#2 --> sb_writers#3 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#3); lock(&ovl_i_mutex_dir_key[depth]#2); lock(sb_writers#3); lock(&p->lock); *** DEADLOCK *** 1 lock held by syz-executor.0/16936: #0: 00000000040ef17f (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2779 [inline] #0: 00000000040ef17f (sb_writers#3){.+.+}, at: do_sendfile+0x97d/0xc30 fs/read_write.c:1446 stack backtrace: CPU: 0 PID: 16936 Comm: syz-executor.0 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2420 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 __mutex_lock_common kernel/locking/mutex.c:937 [inline] __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078 seq_read+0x6b/0x11c0 fs/seq_file.c:164 proc_reg_read+0x1bd/0x2d0 fs/proc/inode.c:231 do_loop_readv_writev fs/read_write.c:701 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_read+0x471/0x630 fs/read_write.c:925 vfs_readv+0xe5/0x150 fs/read_write.c:987 kernel_readv fs/splice.c:362 [inline] default_file_splice_read+0x457/0xa00 fs/splice.c:417 do_splice_to+0x10e/0x160 fs/splice.c:881 splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959 do_splice_direct+0x1a7/0x270 fs/splice.c:1068 do_sendfile+0x550/0xc30 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f5d6fb67209 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5d6e4bb168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f5d6fc7a030 RCX: 00007f5d6fb67209 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000006 RBP: 00007f5d6fbc1161 R08: 0000000000000000 R09: 0000000000000000 R10: 4000000000010046 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffec2f29e2f R14: 00007f5d6e4bb300 R15: 0000000000022000 bridge0: port 3(batadv0) entered blocking state bridge0: port 3(batadv0) entered disabled state device batadv0 entered promiscuous mode bridge0: port 3(batadv0) entered blocking state bridge0: port 3(batadv0) entered forwarding state befs: Unrecognized mount option "âridge0" or missing value befs: Unrecognized mount option "âridge0" or missing value batman_adv: batadv0: No IGMP Querier present - multicast optimizations disabled batman_adv: batadv0: No MLD Querier present - multicast optimizations disabled befs: Unrecognized mount option "âridge0" or missing value befs: Unrecognized mount option "âridge0" or missing value befs: Unrecognized mount option "âridge0" or missing value befs: Unrecognized mount option "âridge0" or missing value EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize 9pnet_virtio: no channels available for device 127.0.0.1 EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize BTRFS info (device loop3): setting 8 feature flag BTRFS info (device loop3): force lzo compression, level 0 BTRFS info (device loop3): disabling tree log BTRFS info (device loop3): disk space caching is enabled BTRFS info (device loop3): has skinny extents 9pnet_virtio: no channels available for device 127.0.0.1 EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize 9pnet: Insufficient options for proto=fd 9pnet_virtio: no channels available for device 127.0.0.1 EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize 9pnet_virtio: no channels available for device 127.0.0.1 overlayfs: failed to resolve './file0': -2 9pnet: Insufficient options for proto=fd 9pnet_virtio: no channels available for device 127.0.0.1 overlayfs: failed to resolve './file0': -2 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet: Insufficient options for proto=fd 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 EXT4-fs warning: 15 callbacks suppressed EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 ieee802154 phy0 wpan0: encryption failed: -22 ieee802154 phy1 wpan1: encryption failed: -22 EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize 9pnet_virtio: no channels available for device 127.0.0.1 EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 EXT4-fs warning (device sda1): ext4_group_add:1682: No reserved GDT blocks, can't resize 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1